Furrrr sound from speaker

[sudhirbhosale]

Hi
At high level mid-woofer driver is moving rapidly and giving getting furrr.... sound. (not sure what is technical term for this )
What is reason and solution for this.
My speaker is 2way DIY with 6" and 1" peerless drivers. WOOFER - S16NI TWEETER T26SG. Both are looking good on specs i.e. low fs and good frequency response range

Using 1st order crossover. Crossing around 2.65 Khz

Is it because of any of below reason?
1. Cone break up
2. Crossover is 1st order
3. 8 ohm woofer and 6 ohm tweer make effective impedance less than 4 ohm as they are in parallel. It is causing any impedance mismatch?
4. Any other probable problem

Thank You !!

 

[Audio_Freek]

The issue should be in Crossover Mostly.

Did you check the Mid-woofer direct?
Did you exchange the Crossovers and check?

 

[sudhirbhosale]

Yes I checked the mid-woofer direct. Same issue is there except it appears at different sound level.
Also changed x-overs.

 

[Audio_Freek]

Thats Bad, Then we need to go for more checks before what gone actually wrong.Though I could say the Crossover could be trouble here, as most of the drivers distort without whistle pushing volume.

1.Check whether the Output from the Amp is troubling(With cross over and without crossover),This can be done by exchanging the Drivers across the Left and RIght output.

 

[keith_correa]

Overexcursion?

 

[rajesh srinivas]

Hi
At high level mid-woofer driver is moving rapidly and giving getting furrr.... sound. (not sure what is technical term for this )
What is reason and solution for this.
My speaker is 2way DIY with 6" and 1" peerless drivers. WOOFER - S16NI TWEETER T26SG. Both are looking good on specs i.e. low fs and good frequency response range

Using 1st order crossover. Crossing around 2.65 Khz

Is it because of any of below reason?
1. Cone break up
2. Crossover is 1st order
3. 8 ohm woofer and 6 ohm tweer make effective impedance less than 4 ohm as they are in parallel. It is causing any impedance mismatch?
4. Any other probable problem

Thank You !!

To perfectly match 2 way drivers the following points are important.

1. matching the impedance ,as woofer is 8ohm and tweeter is 6 ohm this can be corrected in xover by adding a 2ohm resistor in series to the tweeter.
2. even the sensitivity of the driver i.e woofer has sensitivity of 90db whereas tweeter is 93.98 db,again this difference of 4db has to be attenuated in the xover or else one will try to dominate the other.
3. its better if you use 1st order xover for the woofer and for tweeter 2nd order recommended.
4. the crossing of the tweeter seems to be fine.

I suspect the voice coil burn issue,may be the output/load of the amp is too much for these drivers.check also if the cone is ok pics if posted will be fine..

R/S

 

[bornfi]

Hi
At high level mid-woofer driver is moving rapidly and giving getting furrr.... sound. (not sure what is technical term for this )
What is reason and solution for this.
My speaker is 2way DIY with 6" and 1" peerless drivers. WOOFER - S16NI TWEETER T26SG. Both are looking good on specs i.e. low fs and good frequency response range

Using 1st order crossover. Crossing around 2.65 Khz

Is it because of any of below reason?
1. Cone break up
2. Crossover is 1st order
3. 8 ohm woofer and 6 ohm tweer make effective impedance less than 4 ohm as they are in parallel. It is causing any impedance mismatch?
4. Any other probable problem

Thank You !!

if this behavior is same on both the speakers, it is called distortion. Either your amp is not able to produce clean signal or your speakers are not able to handle high output produced by your amp. I suggested this assuming that you always had this behavior and not something that started recently.

 

[sudhirbhosale]

Forgot to mention one thing.
Extremely sorry for this miss !
The Furr sound comes at extreme low frequency. I simulated it using frequency generator, so aroung 40-50 Hz this sound comes with high diaphragm movement. Woofer fs is around 40 Hz.
Might be natural resonance process.... If I am correct then is there solution to address this?

 

[omishra]

Check if spider below cone is not detached from diaphragm. Its glued to diaphragm.

 

[yugaaa]

Can you let us know the amplifier you are using ? Are the speakers making the same sound when you connect them to a diff amplifier and pre amplifier ? I think it is a problem with interconnects or if the amp is too old it might be an earthing issue or dry solder joints

 

[Marun]

Change the drivers and check if you still getting the fur sound. If fur continues, then Amp is the culprit.

 

[sudhirbhosale]

Can you let us know the amplifier you are using ? Are the speakers making the same sound when you connect them to a diff amplifier and pre amplifier ? I think it is a problem with interconnects or if the amp is too old it might be an earthing issue or dry solder joints

I am using Astonia 301 amp. 25+25 W. I get furr sound only at low frequency, when I use frequency generator and input sound around 40-50 Hz.

 

[rajesh srinivas]

I am using Astonia 301 amp. 25+25 W. I get furr sound only at low frequency, when I use frequency generator and input sound around 40-50 Hz.

Frequency response of mid woofer s16ni is 80 - 5K Hz,so you cannot cross below 80hz,the best freq to cross mid woofer will be between above 500hz to 2k.

Thats the main reason for your furr sound i hope you got it.

The Nominal Power Handling of the driver is 50 Watts,so the power output of
the amp is perfect to drive them.

Just cross above 500hz and see you will not get the furr sound,for low freq you can add a low mid woofer or woofer to cover freq below 500hz...

r/s.

 

[yugaaa]

Frequency response of mid woofer s16ni is 80 - 5K Hz,so you cannot cross below 80hz,the best freq to cross mid woofer will be between above 500hz to 2k.

Thats the main reason for your furr sound i hope you got it.

The Nominal Power Handling of the driver is 50 Watts,so the power output of
the amp is perfect to drive them.

Just cross above 500hz and see you will not get the furr sound,for low freq you can add a low mid woofer or woofer to cover freq below 500hz...

r/s.

Frequency response has nothing to do with furr sound or technically speaking amplifier oscillation .

The amplifier oscillation occurs when there is an earthing issue in the amp , when there is a blown cap , or when the pre amp ground is not connected to the amp ground

Irrespective of speaker response , power handling , when the volume of the amp is increased to the max , the amp should be silent and no oscillations should occur .